The present invention relates generally to a disposable filtration unit as may be used for laboratory work and the like. In particular the present invention relates to such a filter wherein the filter medium is quickly and easily recoverable.
Disposable filtration units are well known in the art. One such unit for example is identified in U.S. Pat. No. 3,295,686. Generally the unit described in this patent is a disposable filter which is supplied to the user in a sterile package ready for use wherein the filter membrane is sandwiched between component parts of the unit. These component parts are permanently fixed together as by cementing or ultrasonic welding so that an airtight seal is formed about the periphery which prevents leakage of air into the unit at a point downstream of the filter.
Other disposable units have the filter membrane permanently afixed by cementing or by sonic welding to one element of the unit.
While such units are appropriate in cases where the user is interested in recovering the filtrate, such units are not suitable in cases where the user is interested in recovering the material filtered from the liquid. In this respect the construction of disposable units of the prior art does not facilitate removal of the filter sheet. With these prior art units, attempts to recover the filter sheet often result in a destruction of the filter sheet and the loss of some of the material which the user desires to recover.